#include <iostream>

void test01()
{
    using namespace std;
    string str1 = string();
    cout << "str1 = " << str1 << endl;

    string str2 = string("hello world");
    cout << "str2 = " << str2 << endl;

    const char *array = "helloworld char*";
    string str3 = string(array);
    cout << "str3 = " << str3 << endl;

    string str4 = string(5, 'A');
    cout << "str4 = " << str4 << endl;
}

int main(int argc, char const *argv[])
{
    
    test01();
    return 0;
}
